Golang etcd clientv3库etcd watch演示

FredricZhu · · 1594 次点击 · · 开始浏览

这是一个创建于的文章，其中的信息可能已经有所发展或是发生改变。

Client程序，用来修改watch的值。
注意etcdctrl.exe修改不起作用，必须用clientv3库修改程序才能感知。
所以要做一个Client程序

main.go

package main

import (
    "context"
    "fmt"
    "time"

    "github.com/coreos/etcd/clientv3"
)

func main() {
    cli, err := clientv3.New(clientv3.Config{
        Endpoints:   []string{"localhost:2379", "localhost:22379", "localhost:32379"},
        DialTimeout: time.Duration(5) * time.Second,
    })

    if err != nil {
        fmt.Println("connect failed, err", err)
        return
    }

    fmt.Println("connect success")
    defer cli.Close()

    for {
        ctx, cancel := context.WithCancel(context.Background())
        fmt.Println("Please input xi value:")
        var xiValue string
        fmt.Scanln(&xiValue)

        // 如果输入exit，退出程序
        if xiValue == "exit" {
            break
        }

        _, err = cli.Put(ctx, "/xi", xiValue)
        cancel()
        if err != nil {
            fmt.Println("put failed, err: ", err)
            return
        }

        ctx, cancel = context.WithCancel(context.Background())
        resp, err := cli.Get(ctx, "/xi")
        cancel()

        if err != nil {
            fmt.Println("get failed, err: ", err)
            return
        }
        for _, ev := range resp.Kvs {
            fmt.Printf("%s, %s\n", ev.Key, ev.Value)
        }
    }
}

watch程序 main.go

package main

import (
    "context"
    "fmt"
    "time"

    "github.com/coreos/etcd/clientv3"
)

func main() {
    cli, err := clientv3.New(clientv3.Config{
        Endpoints:   []string{"localhost:2379", "localhost:22379", "localhost:32379"},
        DialTimeout: time.Duration(5) * time.Second,
    })

    if err != nil {
        fmt.Println("connect failed, err", err)
        return
    }

    fmt.Println("connect success")
    defer cli.Close()

    for {
        rch := cli.Watch(context.Background(), "/xi")

        for wresp := range rch {
            err = wresp.Err()
            if err != nil {
                fmt.Println(err)
            }
            for _, ev := range wresp.Events {
                fmt.Printf("%s %q %q\n", ev.Type, ev.Kv.Key, ev.Kv.Value)
            }
        }
    }
}

依赖 go.sum文件

module github.com/zhuge20100104/laonanhai/etcddemo

go 1.15

require (
    github.com/coreos/etcd v3.2.30+incompatible
    github.com/coreos/go-semver v0.3.0 // indirect
    github.com/golang/protobuf v1.4.3 // indirect
    golang.org/x/net v0.0.0-20201031054903-ff519b6c9102 // indirect
    google.golang.org/genproto v0.0.0-20201105153401-9d023cd09d72 // indirect
)

程序输出如下